I have been using SolidWorks and TurboCad Pro to create solid models. They are very precise, but definitely not simple to use. I needed the math driven curves to create the profiles of the teeth of these gears.
#1 (and the first) was done several years ago on the 3D printing system at our local library. Think they charged 25¢ per gram and I guess I got my money's worth.
#2 was done by Shapeways and they finally admitted that they did not have the resolution to print 40 teeth on a disk the size of a penny.
#3-5 were printed by a friend and it took three iterations to get all of the dimensions just right.
The four nubs on the lower side of the disk were used to stabilize the object during printing. These are easily removed with a sanding disk on a Dremel tool. It would be nice to print the shaft with the gear, but I am not sure that it could withstand the torque.
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